Near-Infrared Autofluorescence Identification of Ectopic Parathyroid Lesions

Ectopic parathyroid lesions can be difficult to detect. In the present study, we used near-infrared autofluorescence imaging (NIFI) in three cases of ectopic parathyroid lesions. Our results suggest that NIFI may be a confirmation tool for parathyroid pathology and an intraoperative navigation tool in vivo and ex vivo. Laryngoscope, 134:496-500, 2024.

Intraoperative Parathyroid Gland Identification Using Autofluorescence Imaging in Thyroid Cancer Surgery with Central Neck Dissection: Impact on Post-Operative Hypocalcemia

Hypoparathyroidism is the most frequent complication in thyroid surgery. The aim of this study was to evaluate the impact of intraoperative parathyroid gland identification, using autofluorescence imaging, on the rate of post-operative (PO) hypoparathyroidism in thyroid cancer surgery. Patients undergoing total thyroidectomy with central neck dissection from 2018 to 2022 were included. A prospective cohort of 77 patients operated on using near-infrared autofluorescence (NIRAF+) with the Fluobeam® (Fluoptics, Grenoble, France) system was compared to a retrospective cohort of 94 patients (NIR-). The main outcomes were the rate of PO hypocalcemia, with three cutoffs: corrected calcium (Cac) < 2.10 mmol/L, <2.00 mmol/L and <1.875 mmol/L, and the rate of permanent hypoparathyroidism, at 12 months. The rate of PO Cac < 2.10 mmol/L was statistically lower in the NIRAF+ group, compared to the control group (36% and 60%, p = 0.003, respectively). No statistically significant difference was observed for the other two thresholds. There was a lower rate of permanent hypoparathyroidism in the NIRAF+ group (5% vs. 14% in the control group), although not statistically significant (p = 0.07). NIRAF is a surgically non-invasive adjunct, and can improve patients' outcomes for thyroid cancer surgery by reducing post-operative temporary hypoparathyroidism. Larger prospective studies are warranted to validate our findings.

Feasibility of parathyroid gland autofluorescence imaging after indocyanine green fluorescence angiography

Background

In thyroid surgery, autofluorescence allows the parathyroid glands (PTGs) to be located very early to protect them. Moreover, indocyanine green (ICG) fluorescence angiography (ICG-FA) allows for assessing the viability of the PTGs and identifying blood vessels to preserve them. The main limitation of using ICG-FA is that once ICG has been injected, it is no longer possible to observe PTG autofluorescence using existing devices. This study aimed to describe an approach that allows for visualization of the PTGs by autofluorescence, even after ICG injection.

Methods

We redesigned the FLUOBEAM® LX system to excite fluorescence at 685 nm and detect fluorescence between 700 and 900 nm. This device had short-pass filters at 775 nm that helped to split the contributions of the PTG autofluorescence and ICG fluorescence. Tests were performed on extemporaneous PTG preparations placed next to ICG droplets to assess for rejection of the ICG signal.

Results

A low-pass filter at 775 nm detected 60% of the autofluorescence signals and 10% of the ICG signals.

Conclusion

These findings support the possibility of visualizing PTG autofluorescence despite multiple ICG injections and measuring the balance between ICG and autofluorescence signals.

The Year in Surgical Thyroidology: Recent Technological Developments and Future Challenges

Background: The field of surgical and interventional thyroidology is rapidly evolving. In the past few years, we have seen the introduction and establishment of many novel surgical adjuncts, techniques, and disruptive ablative technologies that have impacted the field. Methods: We identified the most influential articles on technological developments in surgical and interventional thyroidology that were published from September 1, 2020, to August 1, 2021. We searched three electronic databases and consulted experts. Results: Major findings are summarized. Continuous intraoperative nerve monitoring (cIONM) lowered the risk of early postoperative vocal cord palsy 1.8-fold and permanent palsy 29 · 4-fold compared with intermittent intraoperative nerve monitoring. Parathyroid autofluorescence yielded a diagnostic odds ratio (OR) of 228.9 for detection of parathyroid glands over visualization, with 96% sensitivity and 92% specificity. There was no significant difference in the incidence of major complications between the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transcervical thyroidectomy (1.5% vs. 2.1%, p = 0.75), and a higher body mass index did not lead to a significant increase in the odds of cumulative complication with TOETVA for the overweight (OR = 0.52 [95% confidence interval {CI} 0.17-1.58]) and obese groups (OR = 1.69 [CI 0.74-3.88]). Radiofrequency ablation (RFA) for benign thyroid nodules typically resulted in a 50-85% volume reduction with faster recovery times, less pain levels, and higher social and psychological well-being compared with conventional thyroidectomy at 15 months post-treatment, although physical well-being levels were higher in the conventional thyroidectomy group at this time. RFA for papillary thyroid microcarcinoma showed no significant difference in local tumor progression (1.8% vs. 3.3%, p = 0.209), lymph node metastasis (0.6% vs. 0.6%, p = 1.000), recurrence (1.2% vs. 2.4%, p = 0.244), and 4-year recurrence-free survival rates (98.2% vs. 97.0%, p = 0.223) when compared with transcervical lobectomy. Conclusions: cIONM, parathyroid autofluorescence, transoral vestibular approach thyroid surgery, and RFA for benign and malignant thyroid nodules are some of the latest additions to the surgeon's and interventionalist's armamentarium to manage thyroid disease. These technological advancements demonstrate promise to improve outcomes, decrease complications, and enhance a patient's quality of life, but further rigorous studies are needed to define their utility and value.